This invention relates in general to transportation containers for use with endless conveyor systems, and in particular to vented buckets for use with bucket elevators. Bucket elevators are commonly used in the grain and feed industries, among others, to transport flowable bulk material from an initial deposit location to a distribution location at a height above the deposit location. The deposit location may be, for example, where a farmer makes his delivery to a grain elevator and the distribution location may be, for example, the starting point of the grain-processing cycle at the elevator. At the deposit location, the grain is accumulated in a housing through which an endless conveyor belt passes. Buckets on this endless conveyor belt scoop up the grain and carry it to a higher point. As a container reaches the top of the conveyor belt path and begins its downward travel, the grain in the container is discharged into a head area that is in communication with the distribution location.
Traditional buckets commonly face two challenges when used in endless conveyor systems, such as in grain elevators. First, when loading material into the bucket, air can become trapped between the bottom of the bucket and the incoming material. This trapped pocket of air decreases the volume of material which can be carried in the bucket. Second, when unloading material from the bucket, a vacuum may form between the bottom of the bucket and the exiting material. This vacuum causes material to be retained in the bucket, decreasing the rate of emptying the bucket. These challenges are typically addressed in the industry by incorporating a plurality of vent holes in the bottom of buckets. Vent holes provide a pathway for air to reach and escape from a position between the bottom of the bucket and material loaded in the bucket. Vent holes provide a solution to these challenges, but the solution is not ideal. During normal operation, a relatively small amount of material may escape from a loaded bucket through the vent holes. However, should the elevator pause or cease operation, loaded buckets will empty their material into the bottom of the bucket elevator, potentially plugging the elevator and preventing movement of the conveyor system. It was realized by the inventor that improvements in elevator buckets are needed to address these challenges and provide other important advantages.